This invention relates to magnetic bubble (domain) assemblies and more particularly to a magnetic bubble package arrangement having improved heat control and packaging capabilities.
A magnet bubble package comprises one or more chips or modules containing a layer of garnet-like material formed on a substrate and disposed between bias magnets to provide a bias field normal to the plane of the substrate to establish and maintain bubbles in the garnet-like material. For bubble propagation in the plane of the ferromagnetic material, field drive coils provide rotational in-plane magnetic fields and surround the substrate. Means are also provided to interconnect the chips to one another, if there is more than one chip in the package, to control the circuitry for performing various bubble manipulations in the chips and to connect the memory to the outside world. It is, of course, desirable to maintain the space between these packaged components, ie., coils, chips, interconnect circuitry, etc. as small as possible for a number of reasons, including the reducing power requirements of the field drive coils. It is also recognized, however, that the largest source of heat in the package comes from the drive coils during the operation and that unless this heat is dissipated or controlled, the operating characteristics of the bias magnets and chips are materially and sometimes adversely affected. It is especially desirable to maintain the temperature of the bias magnets as close as possible, to the temperature of the chips so that the bias field will remain constant relative to the chips thus not disrupting the size or disposition of the bubbles.
It is also recognized that in addition to thermal control of the heat in the package, because of the desire to maintain the space between these packaged components as small as possible, manufacturing and packaging tolerances have become more critical and thus it is desirable to have the thermal control material also perform the function of aiding in the packaging of the components.
Accordingly, it is a primary object of this invention to provide a magnetic bubble package with means for controlling and dissipating the heat and for aiding in the packaging of the components.